5 冒號 (colon) 的使用目的：
(a) 用來解釋前句 (例：Grandpa has to go to the hospital again: he needs more tests on his heart.)
(b) 用來列舉項目 (例：We have to do more grocery shopping. We need these items: toilet paper, detergent, and shower gel.)

6. The next day, the army changed the story and said that the material was from a weather balloon.（見第20行）
該氣象球其實隸屬於蒙古計畫，是要偵測蘇聯核子活動的，因此被列為高度機密。
The “UFO” debris found by rancher Mac Brazel in 1947 northwest of Roswell, New Mexico, was in fact a remnant of a balloon flight launched as part of a top-secret program called Project Mogul. Its classified purpose was to try to develop a way to monitor possible Soviet nuclear detonations with the use of low-frequency acoustic microphones placed at high altitudes. No other means of monitoring the nuclear activities of a closed country like the USSR was yet available, and the project was given a high priority.
（摘錄自 http://ufoevidence.org/documents/%20doc379.htm)

7. Not until the 1980s was the Roswell incident mentioned again when several stories were published.（見第23行） Not until ... + V + S 「直到……」否定副詞在句首，主詞動詞要倒裝。

8. Some people said that a spaceship had crashed on some farmland and that three to five alien bodies had been found.（見第24行）
對等連接詞and連接兩個that子句當動詞的受詞時，第一個子句的that可以省略，第二個子句的that則不可以省略。
例：I know (that) he is a nice guy and that he loves you very much.
I told the child (that) it was my responsibility to keep him safe and that I would do everything I could to protect him.

9. On the fiftieth anniversary of the rumors of a spaceship landing, more than 100,000 people gathered in the desert town, where the temperature can reach 110 degrees.（見第33行）

(1) on the fiftieth anniversary of N 在……的五十週年紀念日上
anniversary可用來表示重要事件的週年紀念日，如：結婚、校慶、建國等等，前面的介系詞用on，要強調幾週年要用序數。
例：The U.S. celebrated its 200th anniversary of independence in 1976.
Mr. and Mrs. Chou received a lot of blessings on their fiftieth wedding anniversary last week.

(2) 句中的the desert town指的即是位於美國新墨西哥州的Roswell，因為夠明確，所以where所引導的關係子句為非限定用法，對先行詞town補充相關資訊。非限定的關係子句可由關代who、which或關係副詞when、where來引導。
例：Christmas, which falls on December 25, is a holiday for many people.
Dr. Peterson, who studies plants on the island, is a famous botanist.
Ted’s father was born in 1945, when World War II ended.
The best museum in Taiwan is the National Palace Museum, where you can see many national treasures.

(3) reach = be as high as 高達 此處的reach不可等於arrive in或get to。
例：The property loss caused by a devastating typhoon can reach billions of dollars.

10. They went out in the hot sun to look for the burn mark the spaceship left when it crashed against a rock.（見第35行）crash against N （失事）撞擊……；（海浪）撞擊……crash into N 撞上……
例：During the typhoon, a boat crashed against the rocks offshore and sank.
At night, I like to lie in bed and listen to the waves crashing against the shore.
On Sept. 11, 2001, two hijacked commercial planes crashed into the World Trade Center, causing the two buildings to collapse after a great fire.

11. Perhaps this leads them to believe there are beings who are more intelligent than we are.（見第41行）

(1) lead (+O) to+V 誘使(帶領)某人做……的事。
例：The salesperson led me to believe that it was a worthwhile investment.
What led you to leave your hometown?

(2) lead(+O)to + N 通往；導致
例：Hard work leads to success.
Churchill led the British to victory during World War II.

12. Motel owners in Roswell say a quarter of their visitors come to see the alien landing site.（見第46行）
quarter 是「四分之一」，所以文中a quarter of their visitors是四分之一，也就是二成五的旅客。

因為quarter泛指「四分之一」，所以注意以下各數量的表示有所差別：
cut an apple into quarters 一顆蘋果切成四片
three quarters of an hour 四十五分鐘（即四分之三個鐘頭）
a quarter to seven 六點四十五分（差十五分鐘七點）
a quarter after seven 七點十五分
the first/second quarter of the year 該年度的第一／第二季
a quarter = twenty-five cents 二角五分（美、加的貨幣單位）

14. And the fourth most popular talk show in America is about UFOs and aliens.（見第50行）the + 序數 + 最高級 + 名詞 第……個最……的……
例：She is the second tallest student in our class. She is 175 centimeters tall.
It was the third most powerful hurricane on record.

15. People want to believe we are not alone in the universe, but no facts prove there is life anywhere else.（見第52行）else可用於somebody, anybody, nobody, something, anything, nothing, somewhere, anywhere, nowhere之後，意指「其餘的」。
例：Nobody else is willing to help me. Jane is the only one.
It’s unlikely to see this kind of bird anywhere else. It’s indigenous to Australia.

Vocabulary

I. Words for production
1.
opinion poll 輿論調查
carry out/conduct a poll 執行民調
go to the polls 去投票；進行投票
win a victory at the polls 選舉贏得勝利
poll one million votes 贏得一百萬票

13.
media原為medium的複數形，但是現在意指「大眾媒體」時，後面的動詞可用單數或複數。
the mass media 大眾傳播
news media 新聞媒體
media coverage 媒體報導
例：The media are/is very influential in modern times.
What is newsworthy in one medium may be otherwise in another.
The Internet is now a popular medium for gathering information.